Lock.



W. CURLBTT.

LOCK.

APPLIQATIOI rILnn ma. 5. 190a.

Patented Dec. 22, 1908.

' MAW- me 0pm: PETERS 50., wunmmau, n. c

PATENT oE ioE.

WILLIAM CURLETT, OF SAN FRANCISCO, CALIFORNIA.

LOCK.

Specification of Letters Patent.

Patented Dec. 22, 1908.

Application filed August 5, 1908. Serial No. 447,047.

To all whom it may concern: I

Be it known that I, WILLIAM CURLETT, citizen of the United States,residing at San Francisco, in the county of San li'rancisco and State ofCalifornia, have invented new and useful Improvements in Locks, of whichthe following is a specification.

My invention relates to looks; and it has for its object to provide in alock, simple, inexpensive and easily applied means, adapted to bemanipulated by the key complementary to the lock and when so manipulatedto cover and guard the keyholes, this with a view of preventing theintroduction of a lock picking instrument into the lock and of renderingit impossible for any one to peep through the keyholes.

The invention will be fully understood from the following descriptionand claims when the same are read in connection with the drawings,accompanying and forming part of this specification, in which:

Figure 1 is a sectional view of so much of a look as is necessary toillustrate my invention; the same being taken in a plane at the innerside of the lock bolt, looking outwardly. Fig. 2 is a transverse sectionof the portion of the lock. Fig. 3 is a detail section, taken in a.plane at the inner side of the inner disk comprised in my im rovements.

Similar letters d esignate corresponding parts in all of the views ofthe drawings, referringto which:

A is a portion of a door.

B is an escutcheon on the inner side of the door, equipped with a stopC, for a purpose presently set forth, and D is a lock casing arranged inthe door in the ordinary well known manner. The said casing D isprovided in its inner side wall a with a keyhole b, and in its outerside wall 0 with an alined keyhole d; and it is also provided on theinner side of its inner side wall a with key guides e, and in said innerside with a circular countersink f, which countersink preferablycommunicates with an opening 9 in the bottom wall of the casing for apurpose which will presently appear. In the inner side of the outer sidewall a of the casing is provided a circular countersink h which ispreferably smaller than the countersink f in about the proportionillustrated. It will also be observed by reference to Fig. 3 that thecountersink f in the casing wall a communicates with an opening tin thefront wall of the casing; the said opening i casing walls.

and the before mentioned opening 9 being designed to hold againstlateral deflection or displacement the inner disk hereinafter described.

E is the key complementary to the lock. The said key is preferably ofthe ordinary, well known construction, with the exception that it isprovided on its stem j with a projection 7c designed to bring up againstthe before mentioned stop C on the escutcheon B in the manner and forthe purpose hereinafter described.

F is the outer revoluble disk of my improvements, and G is the innerrevoluble disk thereof. The outer disk F is arranged and adapted to turnin the countersink h in the outer casing wall 0, and is held againstlateral deflection by virtue of its interposition between said casingwall and thelock bolt H. It is provided at l with a keyholecorresponding in shape and size to the keyholes in the The disk G iscountersunk at m to enable it to turn without interference from thebefore mentioned key guides c, and is provided with a keyhole, Fig. 3,which also corresponds in shape and size to the keyholes in the walls ofthe lock casing. Said disk G is adapted to turn in the countersink f andin the openings 9 and i of the casing, and it will be observed that inaddition to holding the disk against lateral movement the said openingsg and i afford bearings which contribute to the facility with which thedisk may be turned.

In the practical use of my improvements, when the door is locked fromthe outside the key is. turned around to its initial position and maythen be withdrawn in the usual manner without closing the keyhole by theguard plate. When, however, the door is locked from the inside it willbe observed that the projection k on the key stem will bring up againstthe stop C on the inner escutcheon B after the key has been turnedthrough about three-quarters of a revolution-i. e., sufficiently far toshoot the bolt II to an extent necessary to lock the door. Inasmuch asthe key rests in the keyholes of the disks F and G, it will be notedthat the said turning of the key will be attended by turning of thedisks, and consequently when the key is stopped as stated, the diskswill cover both ke holes of the lock casing and render it absoutelyimpossible to introduce into the lock casing a lock-picking instrument,and at the same time will preclude an outsider seeing into the roomthrough the keyhole.

It will be gathered from the foregoing that in addition to the practicaladvantages hereinbefore ascribed to my improvements, the same areadvantageous because their application entails but little increase inthe cost of producing the lock; the lock casing being adapted to be castwith the countersinks f and h and the openings 9 and i, and the disks Fand G being adapted to be stamped from' suitable metal.

When deemed desirable, the two disks may be connected through the mediumof a piece it, this in order to enable the disks to turn uniformlytogether.

It will further be gathered from the foregoing that the disks are madedouble so that the lock may, in the usual way, be ap lied to a left-handdoor or a right-hand oor by simply changing the bolt.

The construction herein illustrated and described constitutes the bestpractical embodiment of my invention of which I am cognizant, but it isobvious that in the future practice of the invention such changes in theform, construction and relative arrangement of parts may be made asfairly fall within the scope of my invention as defined in the claimsappended.

Having described my invention, what I claim and desire to secure byLetters-Patent, is:

1. In a lock, the combination with-a casing having inner and outer wallsin which are keyholes, of inner and outer disks, arranged to turn in thecasing and having keyholes alined with each other and adapted toregister with the keyholes in the casing and receive a key.

2. In a lock, the combination with a casing having inner and outer wallsin which are keyholes and also having circular countersinks in the innersides of said walls, and a bolt mounted in the casing and adapted to bemoved by a key placed in the keyholes, of inner and outer revolubledisks, arranged in the countersinks and between the casing walls and thebolt and having keyholes alined with each other and adapted to registerwith the keyholes in the casing and receive a key.

3. In a lock, the combination with 2. casing having inner and outerwalls in which are keyholes, and also having circular countersinks inthe inner sides of said walls and openings in its bottom and back walls'in communication with the inner countersink, and a bolt mounted in thecasing and adapted to be moved by a key placed in the keyholes,

, of an inner revoluble disk arranged in the inner countersink and theopenings of the casing at one side of the bolt, and an outer revolubledisk, arranged in the outer countersink at the opposite side of thebolt; the said disks having keyholes alined with each other and adaptedto register with the keyholes in the casing and receive the key.

4. In a lock, the combination with a casing having inner and outer walls.in which are keyholes, and a stop fixed with respect to the casing, ofinner and outer disks, arranged to turn in the casing and havingkeyholes alined with each other and adapted to register with thekeyholes in the casing, and a key complementary to the lock; said keyhaving on its stem a projection adapted to cooperate with the fixedstop, for the pur ose set forth.

In testimony whereof have hereunto set my hand in presence of twosubscribing witnesses.

WILLIAM CURLETT. Witnesses P. H. PIoDA, EDITH W. BURNHAM.

